1. Field of the Invention
This invention relates to a flat panel display device, and more particularly to a plasma display panel having a bilateral display function that is adaptive for displaying a picture in two directions and a driving apparatus thereof.
2. Description of the Related Art
Generally, a plasma display panel(PDP) radiates a fluorescent body by an ultraviolet with a wavelength of 147 nm generated during a discharge of He+Xe or Ne+Xe gas to thereby display a picture including characters and graphics. Such a PDP permits it to be easily made into a thin film and large-dimension type. Moreover, the PDP provides a very improved picture quality owing to a recent technical development. The PDP can be classified into an alternating current (AC) driving system making a surface discharge and a direct current (DC) driving system in accordance with its driving system.
Referring to FIG. 1, there is shown a PDP driving apparatus of AC system that includes a PDP 10 having a pixel matrix consisting of mxn discharge cells 1. In the PDP 10, m scanning/sustaining electrode lines Y1 to Ym, hereinafter referred to as "Y electrode lines", and m common sustaining electrode lines Z1 to Zm, hereinafter referred to as "Z electrode lines", are alternately formed, in parallel, on an upper glass substrate(not shown). Also, n address electrode lines X1 to Xn, hereinafter referred to as "X electrode line", are formed on a lower substrate(not shown) in a direction perpendicular to the Y electrode lines Y1 to Ym and the Z electrode lines Z1 to Zm. Each of the mxn discharge cells 1 is arranged in a matrix pattern at intersections among the Y electrode lines Y1 to Ym, the Z electrode lines Z1 to Zm and the address electrode lines X1 to Xn. A barrier rib(not shown) is formed on the lower substrate in parallel with X electrode lines X1 to Xn to divide the discharge cells 1 arranged at the vertical direction.
Further, the PDP driving apparatus of AC driving system includes first and second address drivers 6A and 6B connected to the X electrode lines X1 to Xn of the PDP 10, a scanning/sustaining driver 2 connected to the Y electrode lines Y1 to Ym of the PDP 10, and a common sustaining driver 4 connected to the Z electrode lines Z1 to Zm of the PDP 10. The first address driver 6A is connected to odd-numbered address electrode lines X1, X3, . . . , Xn-3, Xn-1 and the second address driver 6B is connected to even-numbered X electrodes X2, X4, . . . , Xn-2, Xn to apply a video data to each X electrode line X1 to Xn. The scanning/sustaining driver 2 is connected to m Y electrode lines Y1 to Ym to select a scanning line to be displayed and to cause a sustaining discharge at the displayed scanning line. The common sustaining driver 4 is commonly connected to m Z sustaining electrode lines Z1 to Zm to apply an identical waveform of voltage signal to all the Z electrode lines Z1 to Zm, thereby causing a sustaining discharge.
In such a PDP, one frame consists of a number of sub-fields, and a gray level is realized by a combination of the sub-fields. For instance, when it is intended to realize 256 gray levels, one frame interval is time-divided into 8 sub-fields. Further, each of the 8 sub-fields is again divided into an address interval and a sustaining interval. A discharge initiated at each of the discharge cells selected in the address interval is sustained during the sustaining interval. The sustaining interval is lengthened by an interval corresponding to 2.sup.n depending on a weighting value of each sub-field. In other words, the sustaining interval involved in each of first to eighth sub-fields increases at a ratio of 2.sup.0, 2.sup.1, 2.sup.3, 2.sup.4, 2.sup.5, 2.sup.6 and 2.sup.7. To this end, the number of sustaining pulses generated in the sustaining interval also increases into 2.sup.0, 2.sup.1, 2.sup.3, 2.sup.4, 2.sup.5, 2.sup.6 and 2.sup.7 depending on the sub-fields. The brightness and the chrominance of a displayed image are determined in accordance with a combination of the sub-fields.
Since such a PDP has a wide view angle and favorable to making a large-scale screen, it can be used for a wall tapestry television as well as an advertising display device. In order to apply a PDP to the advertising display device, it is required to maximize an advertisement effect such as a double-faced display function and to improve the brightness.